Polyurethane compositions based on the reaction of polyisocyanates with hydroxylated polybutadienes are well known for use as adhesives, sealants, and coatings for metals and plastics. In conventional polyurethane sealants and adhesives, the polyisocyanate and polyhydroxylated polybutadiene are reacted at near stoichiometric ratios of functional groups (NCO:OH). Because polyhydroxylated polybutadiene polymers are unsaturated, polyurethane sealants and adhesives based on them have limited durability. It is known that durability can be improved by using hydrogenated polyhydroxylated polybutadienes. However, polyurethane sealants and adhesives based on saturated, polyhydroxylated polybutadienes generally have poor tack and low peel strength.
It is an object of the present invention to provide polyurethane sealants and adhesives based on saturated, polyhydroxylated polybutadienes with improved tack and peel strength.